We report the use of enzyme sulfite reductase for the in vitro synthesis of technologically important metal sulfide quantum dots viz. Co3S4, PbS and Ni7S6. Also we report the use of synthetic peptides to control the particle size of the above metal sulfide quantum dots in addition to CdS, synthesized using enzyme. Sulfite reductase when incubated with aqueous CdCl2, or Co(NO3)(3) or NiCl2 or Pb(NO3)(2), and Na2SO3 in the presence of the appropriate capping peptide resulted in the synthesis of particle size controlled CdS, Co3S4, Ni7S6, or PbS quantum dots respectively. These, enzyme mediated synthesized and size controlled metal sulfide quantum dots, were characterized using Absorbance and photoluminescence spectrometry, X-ray diffraction, X-ray photoelectron spectroscopy and High resolution-transmission electron microscopy.